imap4d configuration examples?

[Simon Harrison]

I'm trying (yet again) to setup imap4d. I'm using mailutils 3.10 on
Debian 11 on the server, and mailutils 3.16 at home.

/etc/mailutils.conf (server)

mailbox {
        mailbox-type maildir;
        mailbox-pattern "maildir:///home/${user}/Maildir";
};

program imap4d {

tls     {
        ssl-certificate-file "/etc/letsencrypt/live/mydomain/cert.pem";
        ssl-key-file "/etc/letsencrypt/live/mydomain/privkey.pem";
        ssl-ca-file "/etc/letsencrypt/live/mydomain/chain.pem";
        };

};

imap4d seems to running ok. I was under the impression that I should be
able to connect using my normal unix account on the server:

me@home:~$ mailutils imap
imap> 
imap> connect myserver.tld
imap> capability
CAPA: IMAP4rev1
CAPA: NAMESPACE
CAPA: ID
CAPA: IDLE
CAPA: LITERAL+
CAPA: UNSELECT
CAPA: AUTH=GSSAPI
CAPA: AUTH=ANONYMOUS
CAPA: AUTH=EXTERNAL
CAPA: AUTH=LOGIN
CAPA: AUTH=PLAIN
CAPA: AUTH=SECURID
CAPA: AUTH=DIGEST-MD5
CAPA: AUTH=CRAM-MD5
CAPA: AUTH=SCRAM-SHA-1
CAPA: AUTH=SCRAM-SHA-1-PLUS
CAPA: AUTH=SCRAM-SHA-256
CAPA: AUTH=SCRAM-SHA-256-PLUS
CAPA: AUTH=SAML20
CAPA: AUTH=OPENID20
CAPA: AUTH=GSSAPI
CAPA: AUTH=GS2-KRB5
imap> login simon mypassword
Password:malloc(): unaligned tcache chunk detected
Aborted (core dumped)

Has anyone got a imap4d.conf they can share to hopefully point me in
the right direction to get things working?